Machine for cutting sheet metal.



1.1. L. KRooK.

MACHINE FOR CUTTING SHEET METAL.

l APPLICATION FILED MAY 3I| I9I6 I 1,226,536.L Patented May 15, 1917.

2 SHEETS-SHEET I.

wif/www0 5, 3 0 I I z 3 a 3 2. 2 ggg Patented May 15, 1917 ff s .I J I y I. L. L. KROOK. MACHINE FOR CUTTING-SHEET METAL.

APPLICATION FILED MAY 31| I9I6.

v Sheet Metal,

.io i.. L. moon, orrnoc'roa, vm` n 01W,

Maenner: non eurams snaar Mn'raii. Y

of Vermont, have invented new and useful.

Improvements in Machines for Cutting of which the following is a specication. f

This invention relates to a machine Jfor cutting sheet meta-l, and particularly to a machine for cutting sheet metal into templets,'or performing similar work wherein the material is to be cut along irregular or variously curved lines. i

One object of the invention is to provide a metal cutting machine in which the cutting operation is performed by the use of relatively xed and reciprocating cutting blades, beveled to a prescribed cutting form, and a rapid reciprocating motion is imparted to the movablecuttingblade for cutting the material at Aa desired comparatively rapid speed, lwhereby through the medium` of a small vertical cutting motion in connection with comparatively small shear cutters, small curves may be rapidly and conveniently cut, so that curves of any outline A may be produced with facility and conclaimed, reference bein had to the j panying drawings venience.

A further ob'ect of the invention is to provide means or relativel adjusting the cutting blades, for varyin t e throw or cuttin am? for varying the Ispeed of operation of the movable cutting blade according to its throw or range of cuttingmotion, whereby advantageous results may be secured.

With these and other objects in view, the invention consists of the features of construction, combination and arrangement of fully described and accomin w ich Figure' 1 is a side elevation, with the table show'n in section, of a sheet metal cutting machine embodying my invention. Fig. 2 is a sectional plan view on the line 2-2 of Fig. 1.

Fig. 3 is an enlarged Vvertical longitudinal section through the operating shaft and parts hereinafter showing the eccentric collar.

Fig. 4 is an end elevationof the same.

Figs. 5 and' 6 are sections on the lines 5--5 and6-6of Fi 3, showing the eccentric collar adjusted or maximum and minimum cutting actions.A

Specification of Letters Patent.

Application med may 31, 1916. Serial No. 100,833.

motion of the mova le cutting blade,

Patented May 15, 1917.

Fig. 7 is a detail section on the vline 7 7 of Fig. 1.

Fig. 8 aview showin ithe means for locking the hand wheel emp oyed for adjusting the work table.

Figs. 9 and 10 are detail views in front and side elevation, respectively, of the cutter blades. v

In carrying my invention into practice, I provide a frame structure of a suitable type shown in the present instance as consisting of a post 1 and a pair of superposed brackets 2 and 3 suitably secured thereto. The post 1 is designed in practice to be secured in a vertical position to a wall Yor other suitable stationary support.

The lower bracket 2 is iprovided with a transverse slot 4 opening|through its forward edge, and above said slot has a sleev'e 5 of angular form-in cross section to receive a depending post 8 of similar form depending from a yoke 9 supporting 'the work table- 10, which work table is provided with 'an opening 11 therein in which operate vthe fixed and movable cutting blades 12 and 13. 4

The yoke is provided llwith a socket or holder 14 to receive the cutter 12, which is secured therein by a set. screw 15, while the cutter `blade 13 lits within a socketed holder 16 at the lower end ofa reciprocating carrier` bracket 3, the sleeves 5 and 19 being similar` in construction whereby provision is made to permit vertical adjustment of the table and' vertical reciprocatory motion of the` carrier 1'( without permitting said parts to have any rotary or turning motion, so that atA all times the cutters may .be i'caintained in working alinement with each other. In

practice, each sleeve -5 and 19 may be formed with a cap'piece or removable section 20 se'- cured. in position by screws 21 wherebv provision is made for the ready application and removal of the tableA and reciprocating carrier, as willbe readily understood. The depending`post-8 of the carrier yoke 9 terminates in a threaded stem 2 2 which extends into the slot or opening 4 and receives the threaded hub of an adjusting wheel 23 whereby the table ma be raised and lowered to relatively adjust t e cutters 12 and 13 as may be required to dispose the point ofthe movable cutter so that it will always lap the Afixed, cutter the very smallest degree that is naled horizontally in bearings 31 at the top of the bracket 3, said strap being operated through the medium of the eccentric collar 1to reciprocate the pitman 26 for a ra id,

cuttin motion of the movable cutter b ade 13. he eccentric collar has an loutwardly extending sleeve 32 which lits upon thereduced end 29 of the shaft 30 which is provided with a set screw33 to engage an annular groove 34 and any one of a-.series of seats 35 in said groove whereby the eccentric collar may be axially adjusted on the shaft portion 29 to vary its `eccentric action or degree of throw reciprocation of the itman 26, and locked by the set screw in a justedr position against any possibility .ofycasual displacement. .On the exposed end of the shaft 29 andvsleeve 32 are marked graduations, as seen in Fig. 4, with numeralsopposite one or both sets, the marks being opposite the seats 35; and by inspecting these the operator may readily ascertain how the machine is set .without separating any .parts or looking elsewhere for the information. By means of such adjustments and variations of action of the eccentric, it will be evident -that the movable cutter blade may begiven dierent4 degrees of cutting motion, withm agiven range of a comparatively small maximum cutting'motion, to vary the length of the cuts, so thatby the rapid and continuous formation of largeor small cuts within the maximum limits of cutting motion of the blades, the speed of cutting action depending upon the length of the c`u s, it 4will b'e-ob-` vlous that curves of different us or other cuts along diierently curved or` regular lines may be rapidly and eiiciently 'produced. By this means templets and s imilar objects, ordinarily stamped or cut by saws and the like out of sheet metal, may be much more easily, conveniently and quicklycut without the dangers, expense and loss of time incurred in using saws. Y

In practice, the cutting blades 12I and 13 are preferably made of pecullar construction, the lower or ixed blade 12 beingprovided with a `cutting edge which is beveled at one side and slopes or inclines'at an upward and rearward angle from itsfrontedge, while the movable cutter blade 13 is provided; with a' cutting edge which is beveled also on one vchecked down or stop ed.

to the vfact that thev side andr inclined downwardly and rearwardly at an angle from its front edge, the points or advanced portions of the cutting edges of the blades being opposite to each other, so that in operation .the bladeswill actlwith a shear cut away from their tips or points, and with a degree and length of cut equal to the range of downward motion of the blade 13. An eiiicient cutting action is thus obtained,'-while by rapidly reciproeating. the blade .13 through a very small workmg stroke or range, varying from, say, a thirty-second of an inch to, say, oneeighthl of an inch,` cuts of a len h from one-sixteenth of an inch to oneourth of an inch .may be rapidly'and conveniently made, and which will be suitable in a cutting action for producing long or short curves and irregular outlines of various kinds, thus enabling templets and other plates or articles having'curved or irregularly shaped edges to be produced with great speed,'conven1ence and economy. It is desirable tovarythe speed of operation of the movable cutter accordingto the length of its stroke, a rapid operation being more elicient for a short stroke and a somewhat less rapidit `for `a long stroke,

thus allowing even smal curves to beproduced along an given length of material with great rapi `ty. To this end the operating shaft 30 is providedl with a series of stepped pulleys 36v arranged to be drivenv from a corresponding series of reversely arranged stepped pu eys 37 on a driving shaft 38 through the medium of a connecting -belt or band 39, the stepped Asurfaces of the pulleys having such a coperative or calibrated action with .respect to the diierent adjustments of the eccentric collar as to give exactly the right amount of speed .for any predetermined lenh of cutting stroke. On the operating sha 30 may be employed a hand wheel 39', which may be utilized as a A wheel to secure evennessy of motion and also as a starting wheel, to facilitate the starting of the machine, and as a` brake wheel to enable the machine to be quickly vthe .screw 15, but is'ordinarily not adjustable therein, the adjustmenty of the position connected therewith are raised or lowered as desired. vThe constructlon makes an action of `this cutter bein effected by turning the'.

wheel 23 so that t e table 10' and all partsA possible which may be understood by those A. y

familiar with this art, but which If prefer to explain. Assuming that wewish to cut quite a large hole in the sheet of lmetal remote Afrom its edge, and desire to preserve themetal around the hole. We cannot, in

the circumstances, start to cut in from the edge of the sheet. We first make amark on the hand wheel 23 opposite the wedge 24,

Lacasse turn the hand wheel so as to lower the lower cutter suiciently to leave an opening between its cutting face of the upper cutter, then insert the sheet between the cutters and rotate the hand wheel reversely to cause the cutters to cut a small hole in the sheet.

Now the machine is started, and the cuttersV begin with the small hole and may be caused to `cut an opening of any size, according as the sheet is moved. lt is quite obvious that this possibility would not be. present in they i machine if the original hole had to be cut work to be done than by the use of stamping Y machines or power or other shears or punching devices, and also in enabling work to be done which can not be accomplished by the use of these devices and which is customarily done by means of a fret saw, the objections to which are well known. lt` will also be seen that the invention is advantageous in enabling cuts to be made for curves of any radius, and in providing for variations of adjustment, stroke and speed of the cutters as occasion." may require in producing different curves or irregular surfaces, which adjustments and variations of action may be quickly and conveniently ed'ected.y lt will be further evidenced that the described construction of eccentric means for reciprocating the pitman rod is of great advantage over structures employing crank and slot connections, inasmuch as'bymy construction a much more rapid, smooth and even action may be obtained, and one in which the motion is secured without objectionable noises or strains. While' the construction` disclosed is referred, it will, of 4bourse, bev understood t at changes within the scope of the appendedclaims may be 'made without departing from the spirit or sacriicing any of the advantages et the invention.

. l claim:

l. ln a machine of the class described, the

\ combination with relatively fixed and movable cutters, carriers for them, means for adjusting the carrier of the xed cutter, a guide for the carrier of themovable cutter, a driving shaft having a reduced and ,cranked end and an annular groove whose bottom is curved throughout one portion thereof and provided with seats throughout the remaining portion, an eccentric collar revolubly mounted on said crank and extending over its groove, means for adjusting the position of the collar on the crank,

said means engaging the groove, and operaj A ble connections between the exterior of the collar and the carrier for the movable cutter. 2. ln a machine of the class described, the combination with fixed and movable tools, a

carrier for the movable tool, and a pitman connected with the carrier and havlng an eye at one end; of a power shaft having a crank provided with an annular groove, an eccentric lcollar surrounding the crank and journaled within the eye of said pitmamanda set screw passing radially inward through the collar into l said groove, for the purpose set forth;

3. ln a machine of the class described, thev combination with xed and movable tools, a carrier for the movable tool, and a pitman connected with the carrier; of a power shaft having a crank provided with an annular groove, an eccentric collar surrounding said crank and extended at one end to overlle said groove, an adjustable fastening device in the' extended end of the collar projecting intothev groove and contacting with the bottom thereof, yand a strap inclosing the other end of the collar and connected with said pitman.

d. In a cutting machine, the combination with an upper movable cutter, means for re-l ciprocating it vertically, and means for adjusting the throw of the reciprocations; of a lower cutter, a table having a hole surrounding thisV cutter, a yoke beneath the .table .and having a holder for this cutter, a

post depending from the yoke and threaded at its lower endhan upright guide for the post, a nut on said threaded end belowthe -guide and having a hand-wheel, and a wedge bearing against the hand wheel, for

the purpose set forth. i j

5. lin a machinefor cutting sheet metal, the combination of a fixed cutter, a movable cutter mounted to reciprocate toward and from the xed cutter, a driving shaft having an annular groove whose bottom is formed with a lurality of Vangular surfaces, an eccentric collar mounted for rocutter mounted to reciprocate toward and from the fixed cutter, said cutters having cutting surfaces beveled on their relatively outer sides and inclined at .an angle in lreverse directions, a driving shafthaving a pluralit of angular surfaces, an eccentric mounted for rotary, adjustment on said i shaft, aset screw carried bythe eccentric forengagement with any of said angular surfaces, whereby to vary the'position and throw of the eccentric, a strap actuated by said eccentric, and a working connection between said strap and the movable cutter fo reciprocating the latter. v

7. In a machine of the class described, the combination with relatively fixed and movable cutters, and a driving shaft having near its end a plurality of angular surfaces; of an eccentric collar revolubly mounted on the shaft and inclosing said surfaces, ad-

JOHN L. L. KROOK.

In the presence of-' GEO. M. Soumis, l E. Bumm 

